Hi, I purchased the Bluefruit LE SPI Friend because I require a very small BLE device that has a simple purpose of connecting to a user's phone for only one function. I am now under the impression that this device is only used to add BLE functionality to an existing microcontroller and does not function as a standalone microcontroller itself. I have used the nRF51822 before and had to actually code everything I needed to do in C for the chip itself. I thought perhaps this device made the chip usable via the Arduino IDE for easy integration into projects and that I could still use the chip as a standalone microcontroller.

I'd like to ask if there is any way to achieve that. Adafruit makes their products easy to use with neat custom code, but this sometimes makes it harder to use devices to do something a little different than what Adafruit designed them for. I know that most microcontrollers that are programmed using SPI can then still use those same SPI pins as regular GPIO when the programming is done. I have done that several times. Since this is a little different, I am wondering if anyone might know of a way to program the nRF chip instead of the Arduino and be able to use any of the pins as GPIO once programming is done.

I am aware that I can take a look at the Feather nRF52 Bluefruit LE which looks like it does exactly what I need, but 1) I've already bought the Friend, and 2) the Feather is twice as long and has too many GPIO, both of which I want to cut down on for size constraints.

As you can see from my post, I am not unfamiliar with microcontrollers, and I know of many small packaged uCs, but I stated that I am trying to connect it to my phone. The Bluetooth functionality is a requirement. The Bluefruit Friend is a good board, but I'd like to know if I can use it as a standalone microcontroller and use the BLE functionality together with it.

I know it's a long shot since the library is designed to program the Arduino and not the Bluefruit, but I figure I'd ask in case someone might know of a way to do this.